The increasing demand for new, specialized, biomaterials outpaces their development. One set of successful biomaterials includes those based on polyisobutylene (PIB). Polyisobutylene-containing thermoplastic elastomers, such as poly(styrene-b-isobutylene-b-styrene) (SIBS), have a wide variety of applications as biomaterials due to their unique, bioinert chemistry and broad range of tunable physical properties. One example of a PIB-based biomaterial is the Taxus® coronary stent developed by Boston Scientific, which features a SIBS coating. Its use over the past decade proves the biocompatibility and stability of SIBS in the human body. This long-term biostability is rare among polymers and demonstrates the unique properties of PIB-based polymers.
Certain compounds, such as poly(ethylene glycol), have been used to modify surfaces to improve their biocompatibility and to reduce protein adsorption. However, the surfaces that have been modified have primarily been hard surfaces, such as silicon wafers and gold chips.
There remains a need in the art to reduce protein adsorption for PIB-based polymers. Particularly, certain biomaterials, such as breast implants, are prone to failure by way of capsular contracture. It is believed that the fibrous capsule formation is initiated by the non-specific adsorption of proteins (i.e. fouling), specifically the protein fibrinogen (Fg). Thus, reducing adsorption of Fg will minimize fibrous capsule formation.